LINES GP-CONNECTING 2704347 - Caterpillar

Operation
Illustration 3 g02214294
Swing motor (example)
(2) Piston
(4) Shoe
(5) Shaft
Illustration 4 g02210776
Valve plate (port plate)
(21) Port A
(22) Port B Nine pistons are assembled into the barrel. The end face of the barrel contacts the valve plate. The valve plate has two oval ports (21) and (22). Ports A and B are connected through hydraulic hoses to the swing control valve. When the swing control is activated, the control valve allows oil to flow to the swing motor. Refer to the Systems Operation, "Swing Hydraulic System" for more information on the swing control valve.A swashplate is located opposite the valve plate. Pressure oil flows from the main hydraulic pump through the swing control valve to Port A of the valve plate. The oil flows through the valve plate and the oil enters the cylinder that is aligned with Port A. The oil pushes the piston, and the pushing force is converted into rotary motion by the swashplate. Because the barrel is splined to the drive shaft, the rotary motion is transferred to the drive shaft. The drive shaft then turns the upper structure through a set of planetary gears. The oil flows out of the swing motor through Port B. For the reverse rotation, the oil enters through Port B and the oil exits through Port A.The two relief valves protect the swing motor against pressure spikes.Swing Parking Brake
The swing parking brake is a disc brake. The parking brake is engaged with spring force, and the parking brake is released with pilot pressure. The swing parking brake is released when any of the hydraulic controls are moved except the travel and the blade.
Illustration 5 g02302235
Parking brake (parking brake engaged)
(23) Brake piston
(24) Disc plate
(25) Barrel Disc plate (24) is splined to barrel (25). When the hydraulic oil that flows to the parking brake is shut off, the spring force pushes the brake piston (23) against the case. The barrel and the housing are held against each other by the force of friction, and the drive shaft is locked.
Illustration 6 g02211136
Parking brake (parking brake disengaged)
When all of the hydraulic controls are in the NEUTRAL position, the spring forces the brake piston to engage. Oil is pushed out of the brake chamber through the drain port. This action prevents the swing motor from turning the machine. When any of the hydraulic controls are activated except the travel and the blade, pilot oil enters the pilot port. This action causes the brake to release.Relief Valve
Illustration 7 g02210857
(11) Passage
(12) Relief valve
(20) Passage
(26) Passage
(27) Spring chamber
(28) Piston
(29) Passage
(30) Sleeve
(31) Spring
(32) Valve Relief valves (12) and (15) are located in the top of swing motor (9). The relief valves limit the pressure in the swing circuit to the relief valve pressure setting. This action provides a cushion effect at a start or stop of the swing operation.When the swing joystick is moved back to the NEUTRAL position from the SWING RIGHT position, both the inlet and outlet ports of the swing control valve are closed. No oil flow is supplied to port (17).